Topics

Identify the 3-pin Sealectro power Connector from 454 scope for P6045 probe

Tom Li
 

Hello.

I just purchased a vintage Tektronix P6045 FET probe online. It needs +/-12-volt
power and was designed to be powered from a 3-pin Sealectro power connector on
the 454/454A scope, or a 015-0073-00 power supply.

I'd like to use the probe with my digital scope and feed the +/-12-volt power
externally from my own power supply, without using the original one, however,
I cannot find this Sealectro socket to connect my probe.

TekWiki is unable to confirm it either, it says "The 015-0073-00 (power supply) has
a 3-pin probe power connector (Sealectro 55-850-0018-98?)", note the question mark,
and worse, I was unable to find that Sealectro part.

I asked at the EEVBlog Forum [0], and I was advised to replace the probe power cord.
Since it's an early probe, I'd like to keep it as-is, modifying the probe will be my
the last option, Any suggestion on the candidates for the power connector is
appreciated.

(Sorry if it's a double-post, my original mail seems to be dropped due to technical
problems.)

Thanks,
Tom Li

[0] https://www.eevblog.com/forum/testgear/power-connector-for-tektronix-p6045-probe-454a-scope/

ebrucehunter
 

Tom,
I was in a similar circumstance and was able to purchase one from Q-service in Rhodes, Greece.  The price was reasonable.  You might try them.
Bruce, KG6OJI

uniacke1@...
 

Any chance it's a 3 pin LEMO variant? Tek used these in other probes as well, e.g. P6407

http://w140.com/tekwiki/wiki/LEMO_S-series_connector

catalog:

http://w140.com/lemo_unipole_multipole.pdf

 

Am I missing something?
Did anyone look in the service manual for the part number and the manufacturer code number?
Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of uniacke1 via Groups.Io
Sent: Monday, September 16, 2019 1:32 PM

Any chance it's a 3 pin LEMO variant? Tek used these in other probes as well, e.g. P6407
http://w140.com/tekwiki/wiki/LEMO_S-series_connector
catalog:

http://w140.com/lemo_unipole_multipole.pdf




--
Dennis Tillman W7PF
TekScopes Moderator

Dave Daniel
 

Well, the manufacturer and part numbers are on the mating connectors, so one can tell what they are directly. They are both Sealectro (which is what the OP wrote) with different part numbers for each half. I can see the part numbers, but I can't read them. I'll need to find a magnifier. They are not Lemo connectors.

I don't see the usual Tektronix-to-actual manufacturer list in the manual, and the manual is a bit confusing. I have been trying to decipher it. The Sealectro connectors seem to be called out as single-conductor connectors (item ref. no. 37), but that can't be right. It is shown on the schematic (J60) and shown as a three-pin round connector.

I'm confused. I also have one eye temporarily out of commission,so that is not helping matters.

DaveD

On 9/16/2019 5:48 PM, Dennis Tillman W7PF wrote:
Am I missing something?
Did anyone look in the service manual for the part number and the manufacturer code number?
Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of uniacke1 via Groups.Io
Sent: Monday, September 16, 2019 1:32 PM

Any chance it's a 3 pin LEMO variant? Tek used these in other probes as well, e.g. P6407
http://w140.com/tekwiki/wiki/LEMO_S-series_connector
catalog:

http://w140.com/lemo_unipole_multipole.pdf



 

I have 454 manual document 070-0617-00.

The power sockets are 2 pieces 131-0438-00, shown as part 84 in fig. 1, "Front".
The parts list shows them as "CONNECTOR, 3 contact, female".
In the schematic diagram they can be seen as "U123B" and "J123" in dwg 14
In the mechanical parts list they are shown as "J1238" and "J1239", which makes more sense.

Raymond

Tom Li
 

Thanks for everyone's response.

After some researches in the mailing list archive, currently I highly suspect it's a
LEMO connector, model 303. I've already ordered one EGG.00.303.CLL. I'll update
the thread and report back when my package arrives.

Tom Li.

 

TekWiki is unable to confirm it either, it says "The 015-0073-00 (power supply) has
a 3-pin probe power connector (Sealectro 55-850-0018-98?)", note the question mark,
and worse, I was unable to find that Sealectro part.
The rim of the sockets on one of my 454's is marked "Sealectro" and "950-0019-00".

After some researches in the mailing list archive, currently I highly suspect it's a
LEMO connector, model 303. I've already ordered one EGG.00.303.CLL. I'll update
the thread and report back when my package arrives.
I'm pretty sure it is *not* (compatible with) a Lemo connector: The "Sealectro" has an internal "shim" that the Lemo doesn't have, the Lemo has an "outward dent" in the rim which the 454's doesn't have (it has one in the teflon center body) and the bushings form an equilateral triangle in the 454's, whereas the Lemo 303's contacts as per the catalog drawing don't. I haven't checked exact measures and
unfortunately, I cant suggest a number nor supplier for the 454's sockets.

The later 4-pin probe power sockets are Lemo.

Raymond

 

Correction:
The rim of the sockets on one of my 454's is marked "Sealectro" and "950-0019-86", *not* "950-0019-86".

Raymond

 

This is getting embarrassing, although it's only 2:00 AM where I live:

Correction of my correction a few moments ago:

It should read

"The rim of the sockets on one of my 454's is marked "Sealectro" and "950-0019-86", *not* "950-0019-00".

Raymond

 

The Tek Electro-Mechanical Common Design Parts Catalog (Jan 1989) on page 11-14 "Circular Connectors Multipin - Receptacle" describes it as:
Contacts: 3 Female
Thread Size: 0.354"
Special Features: Snap Lock with Index Mark
Cost: $8.90
Code: CS (meaning Customer Service Replacement Item not used in a current production instrument)

Neither the Common Design Parts Catalog nor the 454 Service Manual has any manufacturer information. This comes as a surprise to me.

Dennis Tillman W7PF

-----Original Message-----
From: Raymond Domp Frank
Sent: Monday, September 16, 2019 4:14 PM

I have 454 manual document 070-0617-00.

The power sockets are 2 pieces 131-0438-00, shown as part 84 in fig. 1, "Front".
The parts list shows them as "CONNECTOR, 3 contact, female".
In the schematic diagram they can be seen as "U123B" and "J123" in dwg 14 In the mechanical parts list they are shown as "J1238" and "J1239", which makes more sense.

Raymond




--
Dennis Tillman W7PF
TekScopes Moderator

Tom Li
 

Raymond Domp Frank said,
I'm pretty sure it is *not* (compatible with) a Lemo connector: The "Sealectro" has an
internal "shim" that the Lemo doesn't have, the Lemo has an "outward dent" in the rim
which the 454's doesn't have (it has one in the teflon center body) and the bushings
form an equilateral triangle in the 454's, whereas the Lemo 303's contacts as per the
catalog drawing don't.
No worries. I think your assessment is indeed correct, I don't think it's even
worth trying, so LEMO model 303 is not compatible with Sealectro 950-0019-86,
I've canceled the order.

The biggest problem is that, in the current catalog from Sealectro, it doesn't
even have a 950 prefix, it seems the series has been permanently discontinued
and there is no information about substitute. I went to Q-service's website as
suggested by Bruce as well, but it requires dedication to find the part in the
huge listings, not to mention the multi-week international shipping.

Now I decide to replace the power cord with a generic one with a DIN connector.
The power cord is not a impedance-controlled coax, replacing it should be straightforward,
getting a shielded cord should work well.

Meanwhile, if anyone has ideas about potentially compatible parts, I would
purchase and test them. I think it may help someone else in the future, my
thread seems to be the only discussion about the 3-pin power connector I
can find on the entire web.

Tom Li